Fig. 2: Algorithm for management of acromegaly. Pharmacological management is undertaken to preserve pituitary function. Preoperative octreotide therapy should be considered if the tumour is invasive or the patient's condition needs to be improved or stabilized. "Active disease" means an IGF-I level of more than 333 µg/L and a plasma growth-hormone level of 2 µg/L or higher during a 2-h oral glucose tolerance test. "Controlled" means an IGF-I level of less than 333 µg/L and a plasma growth-hormone level of 2 µg/L or lower during a 2-h oral glucose tolerance test. Radiotherapy should be considered if there is a lack of preoperative response to drug therapy or if there is coexisting hypopituitarism. Octreotide is used in conjunction with radiotherapy to control disease during the periods between sessions.